Bug 509885

I don't know if these are relevant, but:
Switching to dark mode and then to automatic sets it to Breeze Light.

Works for me; I've been using it for a month or so.

How are you setting this up? From Quick settings, or the Global Themes KCM?

What's your time zone, and have you changed it recently?

Are you making sure to wait 5 seconds after the configured switching time is reached? BY default, it requires 5 seconds of inactivity before switching (this is configurable).

If you restart KDED with `systemctl restart --user plasma-kded6.service`, does it start switching at the correct times?

(In reply to Nate Graham from comment #2)
> Works for me; I've been using it for a month or so.
> 
> How are you setting this up? From Quick settings, or the Global Themes KCM?
> 
> What's your time zone, and have you changed it recently?
> 
> Are you making sure to wait 5 seconds after the configured switching time is
> reached? BY default, it requires 5 seconds of inactivity before switching
> (this is configurable).
> 
> If you restart KDED with `systemctl restart --user plasma-kded6.service`,
> does it start switching at the correct times?

I tried setting it up from both pages.
The timezone hasn't ever changed on this device: CET.
I forgot and didn't wait, but if I wait or uncheck the inactivity checkbox, it still doesn't change.
Restarting kded solves it.

Now that it's working, if you reboot the machine, does it stay working?

(In reply to Nate Graham from comment #4)
> Now that it's working, if you reboot the machine, does it stay working?

No, and apparently restarting kded6 doesn't always solve it

Gross, bugs like this are just the worst!

Can you try running

 plasma-apply-lookandfeel --keep-auto --apply org.kde.breeze.desktop

and

  plasma-apply-lookandfeel --keep-auto --apply org.kde.breezedark.desktop

do they change anything?

(In reply to Vlad Zahorodnii from comment #7)
> Can you try running
> 
>  plasma-apply-lookandfeel --keep-auto --apply org.kde.breeze.desktop
> 
> and
> 
>   plasma-apply-lookandfeel --keep-auto --apply org.kde.breezedark.desktop
> 
> do they change anything?

I turned on the day-night theme during the day, and it changed correctly to light.
However, setting the sunset time to earlier than the current system system didn't cause it to change, and plasmashell crashed: https://crash-reports.kde.org/organizations/kde/issues/260506/events/9817dc44dcbe4c7a9dddfd28aa382f1f/
Running `plasma-apply-lookandfeel --keep-auto --apply org.kde.breezedark.desktop`  caused the theme to change as expected :)

(In reply to aronkvh from comment #8)
> (In reply to Vlad Zahorodnii from comment #7)
> > Can you try running
> > 
> >  plasma-apply-lookandfeel --keep-auto --apply org.kde.breeze.desktop
> > 
> > and
> > 
> >   plasma-apply-lookandfeel --keep-auto --apply org.kde.breezedark.desktop
> > 
> > do they change anything?
> 
> I turned on the day-night theme during the day, and it changed correctly to
> light.
> However, setting the sunset time to earlier than the current system system
> didn't cause it to change, and plasmashell crashed:
> https://crash-reports.kde.org/organizations/kde/issues/260506/events/
> 9817dc44dcbe4c7a9dddfd28aa382f1f/
> Running `plasma-apply-lookandfeel --keep-auto --apply
> org.kde.breezedark.desktop`  caused the theme to change as expected :)

*earlier than the current system time

A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/5875

Can you share your timezone and ~/.config/knighttimerc? also, did you change any global theme related options or can you attach your kdeglobals file to this bug report too?

timezone info can be collected by running `timedatectl` command? if you feel uncomfortable posting this information in public here, can you send an email to me?

s/command?/command./

Git commit cca20d8287e433160468be40fab4a28494b22bb3 by Vlad Zahorodnii.
Committed on 30/09/2025 at 12:44.
Pushed by vladz into branch 'master'.

kcms/lookandfeel: Add some debug messages

M  +8    -0    kcms/lookandfeel/kded/CMakeLists.txt
M  +9    -0    kcms/lookandfeel/kded/lookandfeelautoswitcher.cpp

https://invent.kde.org/plasma/plasma-workspace/-/commit/cca20d8287e433160468be40fab4a28494b22bb3

A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/5877

Created attachment 185400 [details]
kdeglobals

(In reply to Vlad Zahorodnii from comment #11)
> Can you share your timezone and ~/.config/knighttimerc? also, did you change
> any global theme related options or can you attach your kdeglobals file to
> this bug report too?

knighttimerc:
[ManualLocation]
Latitude=45.154058011549154
Longitude=21.010521873235774

[Times]
SunsetStart=20:04:00
TransitionDuration=2400

I set sunset to 20:04 after 20:04 has passed on that day.

timezones:
               Local time: k 2025-09-30 16:46:27 CEST
           Universal time: k 2025-09-30 14:46:27 UTC
                 RTC time: k 2025-09-30 14:46:27
                Time zone: Europe/Budapest (CEST, +0200)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no

Git commit 83e5fb1a0510b5cc7418715d17bbfdc74d689aff by Vlad Zahorodnii.
Committed on 30/09/2025 at 14:31.
Pushed by vladz into branch 'Plasma/6.5'.

kcms/lookandfeel: Add some debug messages


(cherry picked from commit cca20d8287e433160468be40fab4a28494b22bb3)

Co-authored-by: Vlad Zahorodnii <vlad.zahorodnii@kde.org>

M  +8    -0    kcms/lookandfeel/kded/CMakeLists.txt
M  +9    -0    kcms/lookandfeel/kded/lookandfeelautoswitcher.cpp

https://invent.kde.org/plasma/plasma-workspace/-/commit/83e5fb1a0510b5cc7418715d17bbfdc74d689aff

(In reply to aronkvh from comment #17)
> (In reply to Vlad Zahorodnii from comment #11)
> > Can you share your timezone and ~/.config/knighttimerc? also, did you change
> > any global theme related options or can you attach your kdeglobals file to
> > this bug report too?
> 
> knighttimerc:
> [ManualLocation]
> Latitude=45.154058011549154
> Longitude=21.010521873235774
> 
> [Times]
> SunsetStart=20:04:00
> TransitionDuration=2400
> 
> I set sunset to 20:04 after 20:04 has passed on that day.
> 
> timezones:
>                Local time: k 2025-09-30 16:46:27 CEST
>            Universal time: k 2025-09-30 14:46:27 UTC
>                  RTC time: k 2025-09-30 14:46:27
>                 Time zone: Europe/Budapest (CEST, +0200)
> System clock synchronized: yes
>               NTP service: active
>           RTC in local TZ: no

Huh, [ManualLocation] is odd. According to knighttimerc, you're using automatic location mode, so changing the sunset time won't have any effect. I wonder whether KDE Linux has corrupted/outdated knighttime or plasma-workspace packages.

The problem is only with custom times, automatic location seems to work.

(But when it's automatic you can't set a transition duration for night light, is that intended? Since the transition is only for night light, I think that KCM would be a better place for it)

(In reply to Vlad Zahorodnii from comment #19)
> I wonder whether KDE Linux has corrupted/outdated knighttime or plasma-workspace packages.

KDE Linux hadn't gotten any newer builds of KDE software since 2025-09-25 due to https://invent.kde.org/kde-linux/kde-linux/-/issues/371. So if there was a change that might have fixed this since then, KDE Linux users don't have it yet.

(In reply to aronkvh from comment #20)
> The problem is only with custom times, automatic location seems to work.
> 
> (But when it's automatic you can't set a transition duration for night
> light, is that intended? Since the transition is only for night light, I
> think that KCM would be a better place for it)

Transition duration affects automatic theme switching too.

A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/5904

Hi there KDE team!

Confirmed! I'm experiencing the same issue here on Kubuntu, so I'm glad I've found this bugreport!
Everything is perfectly set up on my end, day/night cycle is all set, my day theme is the factory default breeze white, night theme is factory default breeze dark, theme mode is set to auto in the Quick Settings.

The night time has passed by 10minutes now, and the switch didn't happen... Something is not triggering this thing. It's random, because for example yesterday it worked, but the switch wasn't that smooth even than, it was a bit janky/laggy when the theme switch happened.. 

When I saw the 6.5 release notes I was hyped, and I expected this day/night theme switcher to have some kind more quality of a smoother transition into dark mode or vice versa, and not just happen in an instant... Like, give it a 5 sec transition animation or something, because maybe this quick transition is what causes it not to trigger itself, and it sometimes getting stuck in the current theme when the transition is due.

Operating System: Kubuntu 25.10
KDE Plasma Version: 6.5.0
KDE Frameworks Version: 6.19.0
Qt Version: 6.9.2
Kernel Version: 6.17.0-5-generic (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i5-3470 CPU @ 3.20GHz
Memory: 16 GiB of RAM (15.6 GiB usable)
Graphics Processor: Quadro K620
Manufacturer: FUJITSU
Product Name: ESPRIMO E510

See also https://bugs.kde.org/show_bug.cgi?id=510999

*** Bug 510999 has been marked as a duplicate of this bug. ***

Still broken on openSUSE 15.6 using latest  Plasma 6.5.1  from build service.

Operating System: openSUSE Leap 15.6
KDE Plasma Version: 6.5.1
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.4.0-150600.23.73-default (64-bit)
Graphics Platform: X11
Graphics Processor: NVIDIA GeForce RTX 4060 Ti

(In reply to Vadym Krevs from comment #27)
> Still broken on openSUSE 15.6 using latest  Plasma 6.5.1  from build service.

Is night light the only thing that's broken? Do dynamic wallpapers change depending on time of day?

(In reply to Vlad Zahorodnii from comment #28)
> (In reply to Vadym Krevs from comment #27)
> > Still broken on openSUSE 15.6 using latest  Plasma 6.5.1  from build service.
> 
> Is night light the only thing that's broken? Do dynamic wallpapers change
> depending on time of day?

I use Breeze Dark as theme, and a slideshow of my own wallpaper images  (Desktop Folder Settins -> Wallpaper Type = Slideshow) with the "Switch dynamic wallpapers" set to "Based on whether the Plasma style is light or dark". And thus Night light is what is broken for me (as there is no wallpaper switching depending on time of day).  That's why I had raised https://bugs.kde.org/show_bug.cgi?id=510999 as a separate issue but someone marked it as a duplicate of this one.

(In reply to Vadym Krevs from comment #29)
> (In reply to Vlad Zahorodnii from comment #28)
> > (In reply to Vadym Krevs from comment #27)
> > > Still broken on openSUSE 15.6 using latest  Plasma 6.5.1  from build service.
> > 
> > Is night light the only thing that's broken? Do dynamic wallpapers change
> > depending on time of day?
> 
> I use Breeze Dark as theme, and a slideshow of my own wallpaper images 
> (Desktop Folder Settins -> Wallpaper Type = Slideshow) with the "Switch
> dynamic wallpapers" set to "Based on whether the Plasma style is light or
> dark". And thus Night light is what is broken for me (as there is no
> wallpaper switching depending on time of day).  That's why I had raised
> https://bugs.kde.org/show_bug.cgi?id=510999 as a separate issue but someone
> marked it as a duplicate of this one.

Can you please check whether dynamic wallpapers change depending on time of day? Not slideshow.

(In reply to Vlad Zahorodnii from comment #30)
> (In reply to Vadym Krevs from comment #29)
> > (In reply to Vlad Zahorodnii from comment #28)
> > > (In reply to Vadym Krevs from comment #27)
> > > > Still broken on openSUSE 15.6 using latest  Plasma 6.5.1  from build service.
> > > 
> > > Is night light the only thing that's broken? Do dynamic wallpapers change
> > > depending on time of day?
> > 
> > I use Breeze Dark as theme, and a slideshow of my own wallpaper images 
> > (Desktop Folder Settins -> Wallpaper Type = Slideshow) with the "Switch
> > dynamic wallpapers" set to "Based on whether the Plasma style is light or
> > dark". And thus Night light is what is broken for me (as there is no
> > wallpaper switching depending on time of day).  That's why I had raised
> > https://bugs.kde.org/show_bug.cgi?id=510999 as a separate issue but someone
> > marked it as a duplicate of this one.
> 
> Can you please check whether dynamic wallpapers change depending on time of
> day? Not slideshow.

Dynamic wallpapers do change depending on time of day if when "Wallpaper type" is set to "Image" and "Switch dynamic wallpapers" is set to "Based on the day-night cycle".

Okay, it looks like a different issue.